San Pedro Pellado volcano (Chile): seismic swarm reported at volcano with no known historic activity
Friday, Jun 08, 2012
An earthquake swarm with possibly hundreds of small quakes has been detected at Chile's San Pedro-Pellado (or Tatara-San Pedro) volcano. Not many details about this activity are available and reports are in parts contradictory, as the Eruptions Blog who brought this to our attention points out. ... [more]
San Pedro-Pellado volcanoSan Pedro-Pellado volcano (also known as San Pedro-Tatara) and is a stratovolcanoe in central Chile, located within the 6 x 12 km Río Colorado caldera.
San Pedro stratovolcano has a glacier-filled crater and fumaroles on the SE side of Pellado volcano, an older, eroded predecessor volcano. San Pedro overlies a basal shield of basalt flows. The most recent activity built a young scoria cone some time during the past 10,000 years, but there are no historical eruptions.
Note: there is a volcano with a similar name "San Pedro" in Chile.
Background:The San Pedro-Pellado volcanic complex has been active since about 5 million years ago. It overlies the deeply eroded Pellado stratovolcano; both were constructed within the 6 x 12 km Río Colorado caldera. The caldera formed during a large explosive eruption about 0.5 million years ago.
The Tatara basaltic-andesite shield volcano at the western end of the complex contains up to 100 or more lava flows reaching a total thickness of up to 1500 m.
The dominantly andesitic San Pedro stratovolcano overlies the Tatara edifice.
A major Holocene east-flank debris avalanche filled the Río de la Puente valley to the south and was followed by eruptions from within the avalanche scarp low on the east flank. It produced lava flows down the Estero Pellado drainage.